A few years ago, the automotive industry began to reverse the trend, which it had begun almost twenty years before, of replacing dashboard gauges with small warning lights or so-called "idiot lights". In part this was due to the sophistication of electronic gauges. Electronics are now used in various subassembly components of the modern day vehicle instrument panel. Electronic modules are used as small on-board computers that monitor hundreds of inputs from various sensors on the vehicle. Many leads or wires are used to electrically convey information from sensors at the sources of the information to the electronic gauges, through relays monitored by the modules. Other electronic subassemblies, such as radios, message centers, power antennae relays, intermittent windshield wiper controls, electronic air conditioning switches and relays, and other subassembly components are also interconnected by leads and wiring to electrical sources and sensors.
Because of the sheer number of electrically conductive wires used to electronically connect the subassembly components to each other and to other vehicle electrical components, wiring harnesses are typically used to arrange the conductive wires in groups. The wiring harnesses are attached the instrument panel and routed along its substructure during assembly of the board or instrument panel. Wiring harnesses have the advantage of bringing some order to a spaghetti-like entanglement of wires, facilitating some tracing of the wires to allow for proper connections during assembly and to allow for trouble shooting such connections for repair.
While wiring harnesses have advantages over loose arrays of wires that are difficult to trace, wiring harnesses also have shortcomings. Manually attaching and routing the wiring harnesses is a tedious and labor intensive task. Furthermore, owing in part to the tediousness and labor intensiveness of the task, manual manipulation of the wiring harnesses during assembly often results in damage to the instrument panel, to the subassembly components, and to the wires themselves. Because of the number of subassembly components that must be electrically interconnected, it is of limited advantage to systematize the deployment of wires simply by restraining wires as is done by using wiring harnesses.
For example, bunching a number of wires in a wiring harness does not help in allowing work operations to be performed upon the ends of the wires. This shortcoming can be appreciated by considering the teaching of U.S. Pat. No. 3,956,822, issued to Folk on May, 18, 1976. Folk discloses a method and apparatus for positioning lengths of individual leads of a plurality of leads in spaced apart relationships with respect to one another, so that work operations can be simultaneously performed on the ends of the leads. The lengths of leads are positioned in a plurality of spaced apart grooves of a template by progressively positioning successive parts of the lengths of each of the plurality of leads into respective grooves. Each groove is wider and deeper than the lead positioned within the groove. Each of the grooves has one or more spaced-apart lead confining means that retain segments of the leads positioned in the groove. The template with its grooves are only employed to perform the work operations on the ends of the leads. When the work operations are complete, knockout pins are associated with each of the spaced apart lead retaining means to facilitate stripping the leads from the template. Accordingly, a wiring harness does not facilitate end operations of leads, such as the installation of terminals. As disclosed in the related U.S. patent application entitled "Wiring System for Automotive Instrument Panel Wire", cited in the Cross Reference to Related Applications section of this specification, a system of grooves or troughs as used in the present invention has advantages over both work templates and wiring harnesses.
Several devices have been disclosed as means for automatically feeding wires, cutting them and positioning them on wiring boards, thereby to eliminate the labor intensiveness of routing wires to electrical subassembly components to complete circuits. For one example, Alderman et al., in U.S. Pat. No. 2,896,213, disclose a machine for cutting, forming, and inserting the leads of lead bearing components in a workpiece. The machine has means provided for supporting a wiring board in a pre-determined position relative to operating instrumentalities mounted on the machine head. This relative positioning allows components to formed and applied with their leads extending to or through the wiring boards for suitable connection with circuitry on the mounting boards. The board is mounted on a pallet that is associated with a pair of conveyor belts to move the board into its position.
In U.S. Pat. No. 4,271,573, von Roesgen discloses a quick-connect interconnection system. By this system, all interconnections are performed on one side of a component-receiving board, using slotted-beam insulation-piercing connectors. Boards with or without metalization patterns are adapted to the basic approach. Using boards with an X-Y pattern of holes arranged in columns, slotted-beam connector elements are readily pressed into one side, and corresponding circuit elements, such as dual-in-line packs, plugged from the other side into the connector elements. The system is enhanced by a tool that feeds insulated conductors from a source and into selected slotted beams. The tool includes a retractable knife or a retractable cutter with which a given wire run may be terminated. For the manual mode, a sequence of wiring is indicated to an operator by stepping of a laser beam that illuminates slotted-beams to be interconnected.
Rock, in U.S. Pat. No. 4,461,061, teaches a method and apparatus for connecting wiring to insulation displaced-type, circuit board-mounted electrical contacts. The Rock method comprises automatic positioning and orientating of individual contacts relative to a wire insertion head. A portion of the wire is fed from a supply to the tip of a pusher which inserts this portion into fingers of the contact. Another contact is positioned and oriented relative to the pusher to receive a second portion of the wire and provide a wire run between the contacts. The wire run can be terminated at the last contact without repositioning the contact and pusher relative to each other, with the remaining supply wire being prepared for another insertion. The Rock device and method is similar to that of von Roesgen, and furthermore, Rock does not teach the use of troughs with restraining means.
Aceti et al., in U.S. Pat. No. 4,703,543, discloses a robotically operated wire insertion apparatus for insulation displacement terminals. The Aceti et al. system automatically feeds wire to a wire insertion hand. The apparatus automatically straightens the wire during the feeding so that the wire is aligned with the hand. The apparatus inserts the wire progressively into a plurality of insulation displacement terminals and severs the wire from the last inserted insulation displacement terminal. The apparatus is initialized to begin a new wiring circuit. The method and system as taught by Aceti et al. is adapted for insulation displacement terminals that have any orientation in any plane on one or more different substrates.
None of these systems, alone or in combination with others, teaches the advantages of the present invention. For example, except that the device disclosed by Alderman et al. is an automated machine for forming and applying leads to a wiring board, the device lacks the structure of a machine adapted for movement through a trough while laying wires as will be shown to be an advantage of the present invention. While the von Roesgen disclosure is relevant for its teaching of the quick-connect interconnection system, as will be seen to be an advantage of the present invention, the von Roesgen disclosure provides no teaching of the overall wiring system of the present invention, including the use troughs and a wire feeding method for laying wires in troughs, notwithstanding its teaching of a cutter with which a given wire run may be terminated. And while Aceti et al. teaches point-to-point wiring in different directions to different terminals, there is no teaching of the trough structure and means of restraint taught by the present invention.